The present disclosure generally relates to downhole fluid flow control and, more particularly, to flow distribution assemblies for use in distributing fluid flow through well screens.
In hydrocarbon production wells, it is often beneficial to regulate the flow of formation fluids from a subterranean formation into a wellbore penetrating the same. A variety of reasons or purposes can necessitate such regulation including, for example, preventing water and/or gas coning, minimizing water and/or gas production, minimizing sand production, minimizing oil production, balancing production from various subterranean zones, equalizing pressure among various subterranean zones, and/or the like.
A number of flow control devices are available for regulating the flow of formation fluids. Some of these devices may be non-discriminating for different types of formation fluids and can simply function as a “gatekeeper” for regulating access to the interior of a wellbore pipe, such as production tubing. Such gatekeeper devices can be simple flow control orifices, nozzles, or on/off valves, or they can be metered to regulate fluid flow over a continuum of flow rates. Such flow control devices are referred to as inflow control devices (“ICD”). Other types of flow control devices can achieve at least some degree of discrimination between different types of formation fluids. Such flow control devices are referred to as autonomous inflow control devices (“AICD”).
Flow control devices may be arranged or otherwise mounted on a base pipe (e.g., production tubing) adjacent a well screen disposed about the base pipe to control the flow of fluid between the exterior and interior of the base pipe. The base pipe may be placed within a wellbore, thereby forming an annulus between the wellbore and the outer diameter of the well screen. During production, formation fluids within the annulus are drawn into the base pipe through the well screen and any flow control devices associated therewith.
The fluids drawn into the well screens will tend to follow the path of least resistance. When a flow control device is placed at the end of a well screen, the path of least resistance for the fluid is to enter the well screen immediately next or closest to the flow control device. As can be appreciated, this can cause very high fluid velocities in the last few inches of the well screen. The actual fluid velocity through the well screen may be dependent upon a number of factors including, but not limited to, the viscosity of the fluid, the gauge of the screen, the type of flow control device used, the size of the flow channel beneath the well screen, and whether the annulus is gravel packed.
The dramatic increase in fluid velocity at the end of the well screen adjacent a flow control device may result in harmful erosion or deformation to the well screen at that location. Such erosion or deformation may ultimately cause the well screen to fail, thereby allowing formation or sand particulates to be produced with desired formation fluids (e.g., hydrocarbons).